Born into a prominent Scottish family on Prince Edward Island, Macdonald rejected his Catholic upbringing and left home when he was eighteen. After three years in Boston as a bookkeeper he headed to Montreal and began to work as a commission agent. By 1868 Macdonald had become the leading manufacturer of chewing tobacco in Canada, and by 1885 he may have been the richest person in the country.

"Sir William Macdonald (1831-1917) is the father of the Canadian tobacco industry and one of the country's foremost educational philanthropists. His contributions to McGill University transformed it into one of the world's foremost research and teaching institutions. William Fong's biography places Macdonald's life in its historical context, painting a vivid portrait of Victorian Canada." "Born into a prominent Scottish family on Prince Edward Island, Macdonald rejected his Catholic upbringing and left home when he was eighteen. After three years in Boston as a bookkeeper he headed to Montreal and began to work as a commission agent. By 1868 Macdonald had become the leading manufacturer of chewing tobacco in Canada, and by 1885 he may have been the richest person in the country." "Macdonald turned to philanthropy when he was in his fifties; his endowments to institutions from Prince Edward Island to British Columbia made professionalism and practical education central to Canadian life. Fong describes in particular how McGill University evolved, largely through Macdonald's financial contributions, from an impoverished institution into an intellectual powerhouse. Most famously, he financed the research that led to Ernest Rutherford's Nobel Prize and to the start of the atomic age. Sir William Macdonald offers the first detailed look at the development of engineering, physics, and law at McGill."--Résumé de l'éditeur.

Variant spellings of MacDonald include McDonald, Macdonald, Macdonell, MacDonell, and McDonell. .

The appointment of John William Dawson as principal in 1855 brought modern ideas of education to Montreal, and he imparted to the emerging institution his own deeep commitment to science. The Molson Hall in 1862, the first Medical School on campus in 1872, the Redpath Museum in 1882, the Macdonald Physics Building, the Redpath Library, and the Macdonald-Workman Engineering Building, all in 1893 were the major external evidences of the great intellectual advances that had been made. Equally, the admission of women students in 1884 marked the immense social developments in Montreal society. An early contribution to elementary teaching through the work of the McGill Nornal School was followed by the institution of examinations for a far-flung network of affiliated secondary schools and by the encouragement and supervision of local colleges. By the time Dawson retired in 1893 McGill's influence was already reaching across the new Dominion of Canada, and the university was ready to make the transition into the twentieth century.